I am very concerned with my F2s running temperature. I remember reading other threads discussing this and recall the superior techs saying not to worry unless it crosses the red line because these bikes naturally want to run hot. But I am worried about my baby. My bike runs at around 60-70% of the temp gauge when I am cruising above 50 mph. When I am cruising around 25 mph it wants to redline at 90- 95% of the temp gauge. And when I am stopped it will go from 50% up to 95% in about 10 seconds of idling. Should I let my bike sit for longer once its warmed just to see if it will go into the red? I'm scurred. At some long stoplights, it will get extremely close to going into the red.

Also (if this matters), I suspect my bike is running lean but I have no where near the mechanics ear/ feel as someone more experienced might have. It just feels a little flat and dry once it is fully warm. I still need to get back into the carbs and see what number jet kit I have to confirm. I have a K and N filter and full muzzy exhaust so I am hoping the previous owner also had a jet kit put in.

I did the obvious things like change oil and flush coolant also. It is still perfoming the same after those changes. It used to only go to 95% temp on the really hot days. Now it's doing it at night when its 20 degrees cooler.

Should I be looking to make some improvements or just continue to ride it hard. Also, how much can a leaned jetting affect temperature? I hope it is just this. I'll check out my jets tomorrow.

Thanks for any input on such a monotonous subject.

 

What's on your bike for an exhaust? What's the filter? Is it rejetted? Also, where do you live?


My bike typically stays around 50% when I am cruising CONTINUOUSLY at 50mph, sometimes even dropping down to 35%-40%.

At a standstill, or even slow moving traffic (under 20mph) my bike will reach 70%.

I've yet to get above 85% (still not red, but close), and that was on the hottest day, with my bikes fan running furiously as I chugged along on a 100 degree day.


Soooooounds to me like your bike isn't cooling properly, along with running hot due to being excessively lean. Just a guestimate though.

 

Is your fan functioning propperly? Mine stopped working about a year ago so i wired it up to be on all the time. My temp gauge only goes up to 50% when i'm riding hard intown. cruising on the highway it stays at about 25%.

if it is working make sure your water pump is pumping coolant. that is, if there is any coolant in it.

good luck

james.

 

Are your carbs sync'd properly? If they're out, this can cause temperatures to rise.

 

ok so I never got around to checking my jets to see if they are indeed modded for my exhaust and air filter. I would much rather just check and see if my cooling system is working. How can I go about finding if my water pump is working? Can I hear it? Can I feel it?

I am pretty sure my fan is still working. I can hear it kick in when I come to a stop.

I read somewhere else that sometimes the coolant will not want to stay in the radiator to cool off, and just keep passing through the system continuously. That may be why my bike is alright when cruising, but gets really hot when stopped? How can I go about figuring this out? Will I have to tool around or can I use some common sense to tell?

 

Hi Antatious,

There are a few things you can check about your coolant system to see what kind of shape it's in. First, I would pull off the hoses and look inside the engine as far as you can. Then you can get a feel for the amount of "crud" that you've got fouling your heat transfer. If the aluminum block is especially bad, it might not be a bad guess that the inside of the radiator is similarly fouled.

The water pump is obviously an important part of the cooling system. If I recall correctly, the water pump cover is down near the shifter linkage. It's a round plate with a hose connection stemming from it. Remove the cover and inspect the blades. (I have not done this personally so I'm not 100% sure what's involved). I'm also not sure whether the gasket needs to be replaced upon reassembly. Or you may need some RTV sealant. Anyway, you're looking for worn or torn blades in the pump. It will be fairly obvious if the pump isn't as it should be.

Another part of the coolant system is the thermostat. If the previous two suggestions don't help, I would remove the thermostat and make sure it's functioning properly. My guess is that you can test it in a pot of boiling water. At room temp, it should be closed. Boiling temp should be fully open.

Oh, and your radiator cap needs to be able to seal. (simplest things first, of course). Maybe a local shop can pressure test it for you? Although it's probably smaller than standard. But at any rate, your radiator cap is just as important as other parts of your coolant system because the coolant must not be allowed to boil. (And raising the pressure prevents this).

One other tidbit. When riding, consciously try and keep your RPM's fairly high. (In the 4-7k range). Underreving our bikes actually causes them to run hotter -- noticably hotter. I know this is probably counter-intuitive, but here's the reasoning. When accelerating, your engine develops the same amount of power whether you use low RPMs or high RPMs. Same amount of power, same amount of fire in the cylinders. And the fire is what causes the heat. But at higher RPMs the water pump is circulating water much more effectively -- it's direct drive. So make sure to buzz your engine!

 

whats the easiest way to make the fan to always run when the bike is on?

 

Thanks for the help, Berga. I am a little apprehensive to take my radiator and water pump apart, but I most definitely will if it is necessary. I have a new question though-

Can I run some water and soap through my system for a few minutes, then drain it? Would this help remove some gunk? I asked the guy about the purple power shtuff and he said he wouldn't run it through a radiator because it may eat the rubber hosing. So I guess my main question is- can I run soapy water through my system, and is that even going to be effective?

Thanks

 

Soap won't clean out radiator build up. The residue build up is a process of heat, water, and metal. Normally the radiator coolant protects the aluminum of your engine from being attacked by hot water. When the coolant breaks down, aluminum or steel (pump blades) oxidizes and falls out or collects in areas where the coolant stream slows down. (Nooks and crannys) Radiator flushes use a chemical to strip out the oxidized material. You then flush the cleaner out and install good anti-freeze. This "gunk" can plug pumps and or thermostats.